Synchronizing of shafts



HLEMP vr51111611111311121116 0F sHAFTs Fi1ed oct.l e. 1921 l Inventor: I-lermamn Lem b5 Patented Oct. 23, l-923.`

UNITED sTaTlazs HERMANN Lm, or

Earn, PENNSYLVANIA, AssIeNoal v'ro GENERAL ELECTRIC ColarANY, A CORPORATION or NEW Yoan.

sYNCHRoNIzIN'G or sHAr'rs.

Application led October.' 6, 1921. `Serial No. 505,709.

To all whom it may concern:

Be it known that I, HERMANN Lmrr, a citizen ofthe United-States, residing at Erie, in the county of Erie, State of Pennsylvania, have invented certain new and useful Improvements in Synchronizing of Shafts, of lwhich the followingis a specification.

The present 'invention relates to the synchronizing of shafts and has forits objectl to provide an improved structureand arrangement whereby a plurality of shafts driven by separate means are tied together so as to insure that they will always revolve at the same speed and in the same relative directions. For a Consideration of what I believe to be novel and my invention,V attentionis directed to the accompanying'description and the claims'appended thereto.

One application of my invention is in connection with internal combustion engines of the opposed pistontype wherein the opposed pistons drive separatel shafts each shaft in turn driving a generator, and in the drawing I have specifically illustrated such application. Engines 'ofl this type (utilizing two separate shafts) are particularly suited for high speed because they are y :easy to balance and all parts are of equal weights and dimensions. It will be understood, however, that the lnvention is no vnecessarily limited thereto.

In the drawing, the figure is a diagrammatic View illustrating my invention.

Referring to the drawing, 1 and 2 are' shafts which are t0 be driven at the same speed and in the same relative direction. They drive electric generators 3 and 4 to which they are directly connected by conplings` 5 and 6, the generators delivering either direct or alternating current. v Shafts 1 and 2 are the crank shafts of an internall combustion engine of the opposed piston type, it being understood that by the opposed piston type of engine I mean any engine arrangement wherein each cylinder structure contains two pistons which move toward and away from a common combustion chamber. I have illustrated such an engine diagramniatically, 7 being the cylinders and 8 and 9 the pistons, the pistons 8`being connected to crank shaft 1 and the pistons 9 to crank shaft 2. The engine structure illustrated is to be taken as indicating any suitable or desired type of engine having pistons which drive two 'crank shafts and since the detail structure of the engine forms no part of the invention, further illustration and description are unnecessary.

- Now, 'according to 'my invention the two shafts are normally synchronized by being electrically connected through preferably three slip rings 0r more if necessary on the respectivek shaftsv which slip rings are electrically connected `to the respective generatorsand to each other. This ties the-two shafts together electricall and insures their rotation vat the same spec and of delivering their power to their generators directly. To l insure synehronism when the engine shuts down with the excitation on the generators ofi' and for starting when the generator elds are excited as motors and also to insure the correct relative directions of rotation of the two shafts when starting, the shafts are lmechanically connected by means of a cross shaft having spiral gear Wheels at its ends which mesh with gear wheels on the engine shafts. T he'cross shaft is made up lof two parts coupled together by a. suitable spring coupling which vwill allow an angular displacement of the shaft parts relatively to sov each other by anl amount a few degrees over and below the electrical angle through which one' generator may be displaced from they other in order to obtain synchronism. The coupling is, however, sufficiently strong that when the engine is shutting down the two shafts will be maintained in symmetrical positions relatively to each other. The coupling shaft, however, is not expected to transmit more than one-'half of the load of the engine, nor any of .it continuously. It will thus be seen that the shafts are synchronized normally by the electrical` connection, the mechanical connection being auxiliary thereto.

The slip'rings for generators 3 and l are indicated at 10 and 11 and the connections at 12. In the particular instance shown it. is desirable that shafts 1 and 2 rotate in opposite directions as indicated by the arrows and connections 1Q are suitably crossed to bring about this result.. cross shaft comprises the twoparts 13 and 14 connected by spring coupling 15 and provided with gear wheels 16 and 17 at its ends which mesh with geary wheels 18 and 19 on shafts 1 and 2. Spring coupling 15 may be of anv suitable type and is illus- The to re n'esent the best embodiment therco but l desire to have it understood thatl the apparatus shown is onliv illustrative and that the invention may be carried out by other means;

llvhat l claim new and desire to secure by Letters Patent ot' the TJnited States, is

1. The combination with two shafts and generators driven thereby, of means for positivelyY n'iaintaining a certain synchronous relation in the rotation ot the two shafts comprising a. inultiphase electrical connection between the respective generator armatures wherebyv said armatures` and consequentliv their respective shafts, are held instep or time-phase` a` supplementariY mechanical connection between the shatts comprising a plurality ot parts, and a spring coupling means inserted therein admitting ot slight angular slip between said shafts whereby the load between them is shared electrically through the multipliase connection and the friction load tending to 4cause slip when idling or startingy and stoping is taken by said mechanical connection.

Q.. rlfh'e combination with two shatts and generators driven thereby, ot means tor svnclnoniz'ingI the shafts comprising slip rings on the shafts which are eectricallv connected to the generators and to each other and av mechanical connection between the two shafts, said mechanical connection comprising a shat't formed ot a pluralitg7 ot garts connected by a. spring,l coupling means.

3. The combination with a plurality et shatts operating' means therefor, and `cenerators driven by the shafts, et' means for synchronizing the shafts and insuring that they rotate in the same relative directions comprisingl parallel electrical and mechanical connecting means between the shafts, said electrical connectingmeans comprisingr a po'yphase alternating iurrent connection between the respective armatures ot the generatorswhereby lsaid shalts are locked in; synchronism while the generators are excited and said mechanical connecting means comprising an anxiliaiw7 shaft Lgeared between said lirst named shafts, a. spring couplingl means inserted therein whereby the coupling torce is shifted to the electrical means while the Igenerators 'are excited and to the mechanical means when not excited.

t The combination with a plurality ot shafts, operating means therefor, and generalors driven by the shafts, ot means tor s vmhronizing the shatts and insuring that they rotate in the same relative directions comprising;n parallel e`ectrical and mechanical connecting means between the shatts, said mechanical connecting means including yieldingI means which permits ay relative anguiar displacement ot the sharlits `greater than the electrical angle through which one generator may be displaced relatively to the other to obtain sym-hronisin.

The combination with an internal comnistion engine havingir opposed pistons, vse )arate shafts driven thereby. and electricl generators driven b v the shafts` ot means tor synchroniziugrV said shal'ts comprising electrical and mechanical coi'incctions between t-he two shafts and in parallel to each other.

G. rlhe combination with au internal combustion engine having opposed pistons. separate shafts driven thereb`\i'. and electric generators driven bv the shal'ts` ot means ior synchronizing said shafts comprising electrical and mechanical connections be- 'tween the two shafts and in parallel to each shafts and a. spring,y couplingv connecting,r

said two parts. in witness whereof, l have hereunto mkv hand this yl-th da)Y of ctober, llQi.

HERMAT LEM i".

lee 

